By-pass control valve



'8, T5964 E. J. 4KIMM 3,150,346

Y.By-Mss eummm. VALVE Filed Dec. 129, 12950 2 sheets-sheet Y2 IN VEN TOR. [IW/7l D J //MM 3,160,346 BY-PASS CONTROL VALVE Ewald J. Kimm, Dayton, Ohio, assigner to United Aircraft Products, Inc., Dayton, Gino, a corporation of Ohio Filed Dec. 29, 1960, Ser. No. 79,292 4 Claims. (Cl. 23d-12) This invention relates to iiuid flow control valves in tiuid circulating systems, and particularly to valves responding to a changing condition of a circulating fluid to direct the fluid in the alternative flow paths, as for example through main and by-pass flow paths,

VAlthough not so limited, the invention has especial application to heat transfer systems utilizing a liquid coolant wherein the liquid is circulated through a heat exchanger when it is in need of cooling and is made to by-pass the heat exchanger when it is not in need of cooling, valve means being provided to sense the temperature of the coolant and to direct and redirect flow in response to temperature change.

j The instant invention is concerned with a valve means las described and has for one of its objects the presenting of a compact unitary valve device incorporating temperature sensing means and uid flow directing means operative as described.

Another object of the invention is to present a by-pass control valve especially characterized by rapid response to signaled temperature change.

Still another object of the invention is to provide a selectively operable override control effective when operated to maintain the valve means in a predetermined position of adjustment irrespective of temperature change.

Other objects and structural details of the invention will appear from the following description when read in connection with the accompanying drawings, wherein:

FIG. 1 is a view, in the main in longitudinal section, of a by-.pass control valve in accordance with a rst illustrated form of the invention;

FIG. 2 is a fragmentary View in longitudinal section of the valve of FIG. 1, taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a view like FIG. 1, showing a second illustrated form of the invention;

FIG. 4 is a view like FIGS. l and 2 showing a third illustrated form of the invention;

FIG. 5 is a top plan view of the valve of FIG. 4;

FIG. 6 is a detail view in longitudinal section, taken substantially along the line 6 6 of FIG. 5;

FIG. 7 is a diagram showing a system in which a bypass valve according to the present invention may find a use; and

FIG. 8 is a detail View, enlarged with respect to FIG. 1, of the pilot valve and Iassociated parts comprised in the FIGS. 1-2 embodiment.

, Referring to the diagram of FIG. 7, a valve means 1t) in accordance with the instant invention is shown therein having external inlet bosses 11 and 12 and a common outlet boss 13. The valve means is a part of an arrangement for cooling a system or space 14 and to this end a liquid coolant is circulated through a flow path 15 of which the system 14 is a part. A pump 16 is interposed in the path `15 to place the liquid under pressure and enforce a positive circulation thereof. Also in the path 15 is a heat exchanger 17 by means of which heat absorbed by the coolant in the system 14 may be removed before the coolant is returned to the system. Beyond heat exchanger 17, path 15 leads to inlet 12 of the valve means 1d and may then be directed from the valve means by way of outlet 13 to the system 14. A by-pass line 1S connects path 15 to the inlet boss 11 and it will be understood that line United StatesgPatent O ICC 18 is termed a by-pass because it is positioned to conduct the circulating coolant directly to valve means 10 and outlet 13 without having to pass through heat exchanger 17.

In accordance with the instant inventive concept, the valve means 1li incorporates temperature sensing means and automatic controls responsive to such means whereby the output of pump 16 is admitted to valve means 10 a1- ternatively by way of inlet 11 or inlet 12 in accordance with the temperature of the. flowing coolant. In the event the heat load at the system 14 is not high and the coolant is not in need of cooling then flow to the valve means 19 is by way of by-pass line 18 and inlet 11, the circulated coolant being under these conditions returned directly to the system 14 without being compelled to pass through heat exchanger 17. Under a rising heat load, however, valve means 10 acts to close off flow at inlet 11 and open ilow at inlet 12 with the result that by-pass line 18 is closed and the circulated coolant is required to follow path 15 in its entirety, including the route through heat exchanger 1'7.

Considering now the structure of valve means 10, in the form illustrated in FIGS. 1 and 2, a body 19 has the several bosses 11, 12 and 13 either formed integrally therewith, as in the case of bosses 11 and 12, or installed therein as in the case of boss 13. In either event, the several bosses are formed to deiine open flow passes com- Arnunicating with respective interior chambers in the valve body. Thus, boss 11 communicates with a chamber 21,

boss 12 with a chamber 22 and boss 13 with a chamber 23. The chambers 21 and 22 are separated by a pair of longitudinally spaced apart internal partition walls 24 and 25. The space between these walls communicates with or lforms a part of chamber 23. Further, this space is in controlled communication with the chambers 21 and 22 by reason of respective opposed openings 26 and 27 (FIGrZ) in the partition walls 24 and 25. The openings 26 and 27 are constructed to provide respectively downwardly and upwardly facing valve seats and a dual valve means 23 is arranged in cooperative relation thereto. The valve means'ZS includes a cylindrical portion 29 having a sliding bearing in an upper partition wall 31 of the body 19. The portion 29terminates at its lower end in a downwardlyfacing tapered formation 32 adapted to seat in and close the opening 27. A reduced diameter extension 33 of the piston element projects through and beyond opening 27 and is formed at its lower end with an upwardly facing tapered portion 34. The latter is disposed beyond or beneath opening 26 and is adapted to seat in and to close such opening. The relationship of the parts is such that the valve portions 32 and 34 are made alternatively elective by lowering and raising motions of the valve means 2S. Thus in a lowered position ofthe valve, portion 32 closes opening 37 and -so precludes communication between chamber 22 and chamber 23. At the same time, however, portion 34 of the valve means stands in an open position with respect to port 26 and communication between chamber 21 and chamber 23 is permitted. Raising of the valve means to an opposite position of adjustment is eifective to close opening 26 `and to open opening 27 with a reversal of the fluid connections to chamber 23.

The valve means 28 accordingly is elicctive to connect the inlets 11 and 12 alternatively to passage 23 and thereby to outlet 13.

Adjustment of the valve means 2S as described is in y part effected by a compression spring 35 which is based on a supplemental body member 36 mounted in a lower partition wall 37 of the body 19. The spring 35 engages valve means 28 on the underside of portion 34 and urges it toward an uppermost position closing opening 26 and opening port 27. Motion of the valve means downward, y

of chamber 39, above piston 38, communicates with a downwardly extending body passage 43 which vterminates in lower partition wall 37 and registers with a continua-` tion 44 thereof (FIG. 8) is supplemental body 36. The continu-ation or extension passage 44 terminates in a supplemental body bore 45 also in communication by reason of a passage 46 with inlet body chamber. 21. The latter is in continuous communication with by-pass line 13 so that pressure uid is continuously admitted to the passage 46. Admitted to passage 44and communicating passage 43, this pressure may enter piston chamber VV39 above piston 38, and acting in oppositon toy the spring 35, force valve means 28 downward to the position illustrated closing opening 27 and opening port 26. It will be understood, in this connection, that opening 26V imposes a restriction yto iiow from inlet 11 to chamber 23 with the resultthat a pressure diterence exists as between chambers 21 a-nd 23. Upon admission of pressure fluid to the upper end of the piston chamber 39, therefore, a resultant pressure is available acting in a direction to force piston 38 downwardly as described. To increase the extent of pressure diierence the piston'element Y28 may,

as here shown, be formed with a restricting head portion 47 above valve portion 34 Vadapted to be received in the opening 26. The head portion 47 exerts substantial amount or" restriction upon uid ow from chamber 21 to chamber 23 and is cut by passages 4providing in eiiect a circumferential series of flow paths thereby. The pressure in chamber -22 similarly is relatively reduced by reason of the restriction Vprovided by heat exchanger 17 and so is unable to communicate vto chamber 23 and passage 42 a pressure resistant to actuating motion of piston 38 as described..V Y

Referring also to FIG. 8, flow through the ,bore between passages 46 and `44 is controlled by a pilot valve 49 slidable in such bore. A bushing 51 is installed in a counterbore 52 at one end of the bore 45 and the other end of the bore opens through supplemental body member 36 into outlet chamber 23. In longitudinally spaced relation to one another on the valve 49 are opposing valve formations 53 and 54 adapted alternatively to engage and seat in opposing ends of the bore 45. A spring device 55 is mounted on one end of the piston-like pilot valve 49 and urges it leftward or in a direction to seat valve portion 53 at one end of the port 45 and to unseat valve portion 54 from the other end of the bore. According to ,this arrangement of the parts communication between the passages 44 and 46 iscut otand passageV 44 is communicated instead to outlet chamber 23. VWith this positionv of the pilot valve 49, therefore, ow of high pressure fluid to the piston chamber 39 is prevented and piston element 28 is enabled to assume an upwardy position of adjustment as influenced by the spring 35. In a reverse position of the pilot valve, that is in the position illustrated wherein valve port-ion v54 seats in and closes the outer end of bore l45 and valve portion53 is unseated withinl counterbore 52, then the passages 44 and 46 are communicated with one another and high pressure fluid from the chamber 21 is free to ow to the piston chamber 39 for actuation of the valve 28 to its lower position.

` sure fluid to the piston chamber 39.

The pilot valve 49 has kan axial stem 56 projecting I through and beyond bushing 51. Adjustably mounted on the stemV 56 is a nut 57 engaged by the bifurcated end of a lever 58. The latter is pivotally mounted on a supheat exchanger or in by-passing relation thereto.

4 port 59 mounted on to form a part of a downwardly extending portion of the supplemental body 36. The lever 58 projects beyond its pivotal connection to support 59 and has a pin 6.1 passed transversely therethrough onu which` is a head 62. The pin 61 is anrintegrated extension of a stem 63 projecting fromthe Ybase of a iiexible bellows 64. The head of the bellows limits against a downwardly extending portion of the supplemental body 36 and is formed with a hollow container like portion 65. Portion 65 and the bellows proper are iiiled with a thermally sensitive iluid having the property of expansion under heat. Alsoforming a part of the bellows assembly, and similarly lled with the expansibie huid, is a tube 66 attached at its one end to the container portion 65 of the bellows and extending upwardly into chamber 23 opposite the space between partition walls 24 and 25' of the body.Y The tube 66 is closed atV its upper end and sup-ported'by a bracket 67 mounted on the projecting end o-f bushing 51. A compression spring 68 is interposed between support 59 and the base of bellows 64. The spring tends to collapse the bellows,

fand, through pin 61 Yand head 62, to rock lever 58 in a clockwise direction. So urged, the lever 58 'acts to draw the pilot valveV 49 to the right whereby to position the parts as illustrated where 'passages 46 and' 44 are intercommunicated withone another. Spring 68 exceeds the spring 55 in strength so that the valve 49 is moved to'such position 'despite the opposition of spring 55.

ln the operation of the pilot valve control, with the liquid coolant unheated,` starting o f the pump 16 finds the bypass opening 26 closed by valve 34 and iinds pilot valve 49j adjusted to interconnect passages 46 and 44.Y As the incoming pressure in chamber 21 isV communicated through passage 46, bore 45 and passage 44 to piston chamber 39 the piston 38 is actuated downwardly to open port 26 and close port 27. Thus the initial flow in the system is by way of by-pass line 1S, directly through the valve 1t) by way of opening 26 and chamber 23 and back to the system 14. As heat developed in the system 14 is transmitted to the circulating coolant the expansible fluid in tube 66 and bellows 64 responds by effecting an expansion of the bellows resulting in an axial movement of stem 63 and pin 61 to the right. Lever 5S follows such movement, under .the urging of spring 55, and, as the temperature of the coolant reaches a-predetermined value, valve 53 seats in vbore 45 Yto interrupt flow of high pres- A-t the same time passage 44 is communicated through'the opposite end of bore 45 to outlet chamber 23. The piston means 28 is in this manner restored to the control of spring 35 which Yshifts the valve to its alternate position of adjustment wherein portion 34 closes port 26v and valve portion 32 opens port 27. Further flow of coolant in the system then is by way of heat exchanger 17 and back to the valve by way of inlet 12 and chamber 22. Flow from chamber 22 to chamber 23 is by wayof the opening 27, and, in passing to the outlet boss 13 the coolant comes in contact with tube 66 and bellows 64. Should the temperature of the circulating coolant'fal'l below a predetermined value the expansive force exerted by they iiuid in tube 66 and in the bellows 64 is lessened Iand spring 68 permitted to recompress the bellows and to exert a corresponding rocking motion of lever Y58 in a direction to reconnect passages `44 and 46. The arrangement is one furnishing rapid response to temperature change in the circulating coolant making it possible to hold the temperature of the coolant closely to |a predetermined value.

The valve has, for simplicity sake, been described as directing the entire coolant flow alternatively through the The sensing of temperative change is continuous, however, and pilot valve 49 may assume intermediate positionseifecting acorresponding positioning of valve means 2S. A modulating effect thereby is gained, a part of the total coolant flow circulating by way of heat exchanger 17 and another part circulating in by-passing relation to the heat exchanger.

Under some circumstances, as for example inthe event of a blocked or misoperating heat exchanger, it may be desirable to circulate the coolant Iby way of the by-pass connection continuously irrespective of coolant temperature. To this end there is mounted on the side of the body 19 an electromagnetic device 69 operable when energized to retract a plunger 71. The latter -is formed with an extension 72 projecting into the body 19 through a latteral opening therein in position to engage one end of the pilot valve 49. The plunger 71 is urged outwardly by a relatively strong spring73 with the result that in the absence of energization of electromagnetic device 69 the pilot valve 49 is held positively in the adjusted position illustrated wherein passages 46 and 44 are intercommunicated with one another. In a normal system operation the by-pass control valve is enabled or prepared for use by an initial energizing of device 69 whereby plunger 71 is retracted and the pilot valve released for thermostatic control.

With the pilot valve 49 held by plunger 71, as described, the action of .the bellows 64 in expanding and contracting as a result of temperature change is unaiected due to the sliding connection between pin 61 and lever 58. Similarly in normal operation, a temperature rise beyond that placing valve 49 in its extreme leftward position is accommodated within bellows 64 by an overtravel thereof relative to lever 58.

FIG. 3 illustrates a form of the invention which is the same as that of FIG. 1 except for the use of a difieren-t form of thermostatic control. In the instance of FIG. 3 abody 74 is formed with an outlet chamber 75, an inlet chamber 76 and an inlet chamber 77 corresponding respectively to the chamber 23, 21 and 22 of the FIG. 1 embodiment. A valve element 78 is actuated by a spring 79 and by a piston 81 to perform in the same manner and to the same end and purpose as the valve means 28 of the FIG. 1 embodiment. Pressure uid for actuation of piston 81 is supplied by a passage 82 alternatively connected to a passage 83 under control of a pilot valve S4 movable in a bushing 85. A stem 86 on the valve 84 has a sleeve 87 pinned lthereto which together with a valve element 8S at the outer end of the pilot valve body form valve formations corresponding to the formations 53 and 54 of FIG. 8. Adjustably mounted on the outer end of the stem 86 is a nut 89 to which is connected one end of a bit-metal strip 91. The other end of .strip 91 is fastened to an upstanding stationary bracket 92, the arrangement being one placing the bi-metal strip in a position in chamber 75 to be freely contacted by iluid ilowing therethrough whether coming from the inlet chamber 76 or the inlet chamber 77. Under the flexing of strip 91, occasioned by temperature changes in the circulating coolant, the pilot valve 84 is adjusted axially to connect passage 82 alternately to high pressure supply passage 33 and to outlet chamber 75, or is adjusted to intermediate positions for modulating flow control. The result, as seen in connection with FIG. l, is to achieve a selective positioning of valve element 7S in accordance with the .temperature of the circulating fluid in order that the temperature of such coolant may be held substantially consant. Flow of high pressure fluid to passage 83 is through a Screen 83a.

An electromagnetic device 93 and plunger 94 actuated thereby operate in the same manner and to the same end as corresponding elements disclosed in FIG. l.

FIG. 4 illustrates a further form of the invention utilizing like principles of operation and similar structure. According to this form of the invention, a body 95 provides a vertical bearing for a piston-like sleeve 96. At the bottom of the body 9S a closure device 97 provides a base for a compression spring 98 which urges the sleeve 96 upward within the body. Longitudinal adjustment of the sleeve serves to connect the interior thereof alternately with inlet chambers 99 and 101 located respectively below and above Aan intennediate bearing wall 102 and supplied respectively by inlets 103 and 104. Communication between such chambers and the interior of sleeve 96 is accomplished through vertically spaced apart circumferential series of openings 105 and 106 adapted to be projected respectively below and above the intermediate wall 102 in response to vertical longitudinal adjustment of the sleeve 96. The bottom of sleeve 96 is open and is communicated through a passage 107 in closure 97 with outlet opening-10S.

A passageway 109 in closure 97 opens at its one end into outlet passage or chamber 107 and communicates at its opposite end with a vertically extending body passage 111. The latter extends upward and opens into a chamber 112 above the closed end of sleeve 96. Simultaneously therewith the passage 111 is in relatively restricted communication with inlet 103 by virtue of a. small diameter lateral opening 113 (see FIGS. 5 and 6).

Passageway 109 in closurek 97 intersects a bore 114 and a pilot valve is adapted to move in such bore to interrupt communication between portions of the passagevway 109 in such manner as alternatively to connect and disconnect it from outlet passage 107. Occupying an open position with respect to Ypassageway 109, the-valve 115 prevents a build up of pressure in chamber 112 above sleeve 96. In a closed position the pilot valve in eiect 4interrupts outiiow from the passage 111 so that the pressure entering this passage through restricted port 113 is enabled to. build upa pressure in chamber 112 greater vthan the resistance of spring 98. When this occurs the sleeve 96 is moved downward altering the relationship of inlet chambers 99 and 101 to outlet passage or chamber 107. The adjustment of pilot valve 115 is under control of a bi-rnetal strip 116 mounted on a bracket 117 extending upwardly within sleeve 96 from the closure member 97. The mode of operation of the device of FIG. 4 is essentially the same as those of FIGS. 1 and 3 and the function in a liquid coolant circulating system as described in the same.

In FIG. 4 an electromagnetic device 118 controls, through its reciprocable plunger 119, fluid ow from inlet 103 to chamber 112 by way of a passage 121, recess 122 and port 123. In an extended or seated position as shown the plunger 119 closes passage 121 and so denies direct access of the pressure uid at inlet 103 to chamber 112. In this position of the parts, therefore, the valve means is free to operate in its intended manner under the inuence of thermostatic strip 116 and pilot valve 115. Upon energizing of the device 118, however, valve 119 is retracted and relatively unrestricted fluid under pressure is applied in chamber 112 to effect an immediate movement of the sleeve 96 to its downward position interconnecting inlet 103 to passage 107. As long as the device 118 remains energized the valve means will continue to be so adjusted and to so direct iluid ow irrespective of temperature change.

What is claimed is:A

l. A by-pass iluid control valve, including a body hav- `ing a pair of iluid inlets supplied with a pressure liuid under differential pressure and a common outlet, valve means occupying alternate extreme positions of adjustment connecting different ones of said inlets to said outlet and positions intermediate said extreme postions, spring means urging said valve means toward a position communicating the inlet of lower pressure to said outlet, said body providing a piston chamber directly communicating at its one end with said outlet, said body further providing a passage to the other end of said chamber in common communication with the inlet of higher pressure and with said outlet, means restricting the communication of said passage with said inlet of higher pressure, an adjustable pilot valve opening and closing communication of said passage with said outlet, means responsive to the temperature of the uid for adjusting said pilot valve, and a piston in said piston chamber connected to said valve means and arranged to move said valve means Ytoward the other one of its alternate positions responsive to a. rising pressure in the said other end of said piston chamber upon closing of said pilot valve.

2. A by-pass liuid control valve, includingv a body having a pair of uid inlets supplied with a .pressure fluid under diierential pressure and a common outlet, valve means occupying alternate positions of adjustment connecting different ones of said inlet to said outlet and positions intermediate said alternate position, spring means urging said valve means toward a position communicating the inlet of lower pressure to said outlet, a pressure fluid operated device for moving said valve means toward the kother one of its alternate positions, said valve means being constructed to impose a pressure drop between the inlet of higher pressure and said outlet in the said other one of its alternate positions,said pressure fluid operated device including a piston exposed on'its one side tothe pressure at said outlet, a pilot valve settable to positions exposing the other side of said piston to the pressure' at said outlet and to the pressure at said inlet of higher pressure, and means responsive to the temperature of the uid at said outlet for setting said pilot valve.

3. A by-pass control valve according to claim 2, characterized by selectively operable means maintaining a continuous flow of high pressure fluid to said piston irrespective of the fluid temperature.

4. A by-pass uid control valve,` including a body hav-i ing a pair of fluid inlets supplied With a pressure iluid under Vdiilerential pressure and arcommon outlet, valve means occupying alternate extreme positions of adjustment connecting dierent ones of `said inlets to said outlet and positions intermediate said extreme positions, spring means urging said valve means toward', a position communicating the inlet of 'lower pressure to said outlet, said body providing a piston chamber communicating at `means including a bellows supported by said body and connected to said pilot valve, said bellows being lled with a thermally sensitive fluid and including a tube extension projecting Within the ,body to be contacted by the fluid ilowing beyond saidvalve means toward said outlet.

References Cited in theile of this patentV UNITED STATES PATENTS v1,311,809 Giesler July 29, 1919 1,819,045 Snediker Aug. 18, 1931 1,853,194 Bogle Apr. 12, 1932 1,939,970 Fuess Dec. 19, 1933 1,990,653 Kollsman Feb. 12, 1935 2,127,162 Beauregard Aug. 16, 1938 2,308,165 Fields Jan. 12, 1943 Y2,415,994 Curtis Feb. 18, 1947 2,449,766 Brown Sept. 21, 1948 2,461,615 Taylor Feb. 15, 1949 2,507,621 Branson May 16, 1950 2,698,717 v Sisco lan. 4, 1955 2,810,523 Branson Oct. 22, 1957 FOREIGN PATENTS 226,569 Australia Jan. 8, 1959 705,175 Great Britain Mar. 10, 1954 720,112 France Dec. 3, 1931 

1. A BY-PASS FLUID CONTROL VALVE, INCLUDING A BODY HAVING A PAIR OF FLUID INLETS SUPPLIED WITH A PRESSURE FLUID UNDER DIFFERENTIAL PRESSURE AND A COMMON OUTLET, VALVE MEANS OCCUPYING ALTERNATE EXTREME POSITIONS OF ADJUSTMENT CONNECTING DIFFERENT ONES OF SAID INLETS TO SAID OUTLET AND POSITIONS INTERMEDIATE SAID EXTREME POSITIONS, SPRING MEANS URGING SAID VALVE MEANS TOWARD A POSITION COMMUNICATING THE INLET OF LOWER PRESSURE TO SAID OUTLET, SAID BODY PROVIDING A PISTON CHAMBER DIRECTLY COMMUNICATING AT ITS ONE END WITH SAID OUTLET, SAID BODY FURTHER PROVIDING A PASSAGE TO THE OTHER END OF SAID CHAMBER IN COMMON COMMUNICATION WITH THE INLET OF HIGHER PRESSURE AND WITH SAID OUTLET, MEANS RESTRICTING THE COMMUNICATION OF SAID PASSAGE WITH SAID INLET OF HIGHER PRESSURE, AN ADJUSTABLE PILOT VALVE OPENING AND CLOSING COMMUNICATION OF SAID PASSAGE WITH SAID OUTLET, MEANS RESPONSIVE TO THE TEMPERATURE OF THE FLUID FOR ADJUSTING SAID PILOT VALVE, AND 